I am here in Durban, South Africa, to report on the just-finished climate-change negotiations. While an agreement was reached, negotiations were in doubt throughout the three final nights. The sticking point was Singapore.

Not Singapore specifically so much, but what Singapore represents. In 1992 Singapore was a rich city-state but not yet a developed one. Nearly 20 years later, Singapore is a financial titan and a global city.

So what should its obligations be to cut greenhouse gas emissions? Under old treaties, such as the Kyoto Protocol, Singapore has none. The essence of the package agreed to here in Durban is that, by 2020, Singapore will have some.

Of course, Singapore in total represents less than 1 percent of global greenhouse gas emissions. But Singapore is joined by countries like South Korea—and even the world's largest greenhouse gas polluter, China—in this category of no obligations.

If the Durban deal brings climate-change negotiations into the 21st century, and if countries like Singapore begin reducing CO2 emissions after 2020, the world may not be quite as unpleasantly warm by the 22nd century.